[clang] [clang][python][test] Move python binding tests to lit framework (PR #142948)

[Jannick Kremer via cfe-commits]

DeinAlptraum wrote:

> I've got no explanation why your explicit raise didn't come through (but then I known very little Python).

Strange, I'll see if I can find out why, but as long as it works also for the expected failure case for you, that's good enough for me.

> am at a bit of a loss how to handle build_target now [...] Don't know if/how I can test this myself.

All the `check-clang-python` did is depend on the `libclang` target and then call unittest, so I think it should be enough to change the `build_target` to `libclang`, and then add another step to the workflow that calls `lit` as you described.
Feel free to abuse the CI to test this until it works.

https://github.com/llvm/llvm-project/pull/142948